Remmy Fulgation stands on the cliff between the harpys and the drakes (-780, 92, 1321). Note: There are some pesky harpy's that hover near him.
Target Remmy and use the Tera-Cog Phonulator to make him talk. You need to be at the right distance from him (-791, 94, 1315), otherwise he commands the Slambot to throw you off the cliff. It might take a few attempts to record the right sentence.
Activate the Sympho-Recalibrator to reconfigure Remmy's captured voice clip.
Target Remmy and activate the Tera-Cog Phonulator once more. The device orders the Slambot to get Remmy.
After Remmy gets killed by the Slambot, right-click his body and get Fulgation's findings (a book called Fulgation's Secrets).